The O diffusivity was deduced from emf measurements performed on solid electrolytic cells at 873 to 1373K. It was found that O diffusion in Ta alloys was slightly decreased by small metallic additions. Several % of Mo had the effect of decreasing the O diffusivity (table 264).

J.S.Lee, C.J.Altstetter: Acta Metallurgica, 1986, 34[1], 131-8